Merge Two Tables with the same columns but different data

Question

I have a table that has the following columns:
Current Table Definition
commonname
family
genus
species
subspecies
code
I have a number of entries that don’t fit the current table definition – that is that they only have a common name or description and a code. These records don’t actually represent a species but are needed for data entry because they represent an object that may be encountered in the study (Bare Ground – which isn’t a species but would need to be recorded if encountered). So I would really like 2 tables:
Table 1 Miscellaneous
name
code
Table 2 Plant Species
commonname
family
genus
species
subspecies
code
I would like two tables so I can enforce certain constraints on my species table like requiring that the family, genus, species, subspecies combination is unique. I can’t do this if I have all the “other” records that don’t have a family, genus, species, or subspecies unless I put in a lot of dummy data into the fields to make each record unique. I don’t really want to do this because these miscellaneous records really don’t represent a specific species.
So – the problem is that while I want this data separate I will need to point a column from another table to the code column in both tables.
How is this best done? Table? View? Merge?

Answer 1

Hi,
Actually you don't have to use scope refs. Sorry but I misunderstood you earlier. Here is a complete example that does exactly what you want. Notice how I added the constraint to the materialized view. Also notice when we try to insert a code in tbl3 that doesn't exist in the view, we get an error. HTH.
SQL> create table tbl1 (name varchar2(10), code varchar2(3) primary key);
Table created.
SQL> create table tbl2 (commonname varchar2(10), code varchar2(3) primary key);
Table created.
SQL> insert into tbl1 values ('n1','c1');
1 row created.
SQL> insert into tbl1 values ('n2','c2');
1 row created.
SQL> insert into tbl1 values ('n3','c3');
1 row created.
SQL> insert into tbl2 values ('name1','c1');
1 row created.
SQL> insert into tbl2 values ('name2','c2');
1 row created.
SQL> insert into tbl2 values ('name3','c3');
1 row created.
SQL> commit;
Commit complete.
SQL> create materialized view view1 as select name, commonname, tbl1.code from tbl1, tbl2 where tbl1.code = tbl2.code;
Materialized view created.
SQL> select * from view1;
NAME COMMONNAME COD
n1 name1 c1
n2 name2 c2
n3 name3 c3
SQL> create table tbl3 (code varchar2(3), record varchar2(1));
Table created.
SQL> alter table view1 add constraint view1pk primary key (code); -- <-Note how I added a constraint to the view
Table altered.
SQL> alter table tbl3 add constraint tbl3fk foreign key (code) references view1(code);
Table altered.
SQL> insert into tbl3 values ('c1','r');
1 row created.
SQL> insert into tbl3 values ('c99','r');
insert into tbl3 values ('c99','r')
ERROR at line 1:
ORA-02291: integrity constraint (RAJS.TBL3FK) violated - parent key not found
SQL> spool of;
-Raj Suchak
[email protected]